This invention relates generally to methods and systems for facilitating transactions at a self-checkout terminal and, more particularly, to methods and systems for facilitating transaction at self-checkout terminals with scales.
Self-checkout terminals at grocery stores and other retail stores are well known. The terminals permit a consumer to present items for purchase to sensors at the terminal so the terminal can identify the items and a corresponding price. When the consumer indicates all items for purchase have been presented to the terminal, a sub-total is accumulated, any taxes and discounts are computed, and a total amount due is displayed for the consumer. The terminal then allows the consumer to select a payment method. The terminal presents menu selections to the consumer so funds are transferred to the retailer""s account. Upon confirmation of payment, the items are released to the consumer.
A self-checkout terminal typically includes a display, a scanner for reading unit price codes (UPC), and a checkout area for holding items once they have been scanned. The checkout area may include a motor driven belt to carry items for which a purchase has been verified to a collection area. The terminal also includes a processor, memory, programmed instructions, and data peripherals to control the operations of the terminal. The programmed instructions may contain modules for querying for item prices, computing totals and performing other functions related to the purchase of items through a self-checkout terminal. Some checkout terminals may also include a security application program that operates to reduce the likelihood that the consumer leaves without scanning all of the items or exchanges scanned items with more expensive items that have not been scanned. In many self-checkout terminals, the surface area of the checkout area or belt has a scale underneath it to help track items during checkout. By monitoring the weight of items placed on the checkout area, the security application is able to determine some actions of the consumer for purposes of detecting fraud or operator error by a consumer. For example, the change in weight detected by the scales of the checkout area may be used to determine the weight of an item just placed on the checkout area. This item weight may then be compared to the weight of the item last scanned that is stored in a database or other memory. If the weights are different, the security application program notifies the consumer and prompts the consumer to remove the item and scan the item again to rectify the discrepancy. Thus, the application program is capable of tracking the scanning of items and their placement on the checkout area through its monitoring of the scales associated with the checkout area.
While this type of item monitoring is useful for security tracking purposes it does have some drawbacks. For one, activities in the vicinity of the scales may affect the accuracy of the weighing operations. For example, vibrations caused by carts or other objects impacting a self-checkout station may oscillate one or more items on the scale and displace the items with respect to the weighing transducers. Other activities that may affect weighing operations include pressure from a consumer""s hand on an item, the serial placement of items on the scale that were purchased at the same time, or air pressure from air ducts located near the checkout station. For example, a consumer may scan a group of three oranges having a single unit price (3 oranges/$1) and then place them one at time on the scales.
Activities like the ones described cause measurements of the weight of items placed on the scales to fluctuate. These fluctuations result in measured weights that do not correspond to the weight stored in association with an item""s bar code or other identifier. In previously known self-checkout stations, the scale control software requires N weight readings within a tolerance T of a weight value stored in association with an item identifier such as its bar code. Fluctuations in weight readings may prevent the accumulation of N readings within a weight sampling period and cause the terminal control software to determine that an item placed on the scales does not correspond to a scanned item. The checkout process is then delayed until the weight of the scanned item is verified. Verification may require rescanning by the consumer after the last item is removed from the items scanned list or it may require the intervention of a cashier or other self-checkout station attendant. Both verification procedures are time-consuming and adversely impact the efficiency of the self-checkout process.
What is needed is a system and method of weighing scanned items that compensates for weighing irregularities caused by activities in the vicinity of the self-checkout station.
What is needed is a system and method for measuring the weight of scanned items at a self-checkout station that reduces the necessity of rescanning items or attendant intervention to verify the weight of an item.
The above-noted limitations of previously known systems and methods for tracking items in the checkout area of a self-checkout terminal have been overcome by a system and method that operate in accordance with the principles of the present invention. The system of the present invention comprises an item verifier for verifying placement of an item on a scale of a self-checkout station and a measurement adjuster operatively coupled to the item verifier for adjusting the item verifier operation in response to an erroneous reading signal from the item verifier.
In one embodiment of the present invention, the measurement adjuster increases the number of samples required by the item verifier for determining the weight of an item. By increasing the number of samples collected before determining the weight of the item, the probability that temporary vibrations will not disturb an accurate weight measurement is increased. For example, if N weight measurements with tolerance T are required to verify the placement of an item on scale then an increase in the number of samples collected provides more time for vibrations to dampen or a consumer""s hand to be removed from the item. In another embodiment of the present invention, the period between samples is increased so an accurate weight measurement may be obtained without interference from vibrations, a consumer""s hand, or the like.
The system of the present invention may be implemented with a self-checkout terminal that includes a display, a bar code scanner, and a checkout scale, all of which are coupled to the processor for the terminal. The checkout scale may include a processor operated by programmed instructions with memory for collecting and analyzing weight data or it may provide the weight data to data peripheral interfaces for the terminal processor. The program memory of the terminal processor may include one or more program modules for determining whether the checkout scale processor requires adjustment. The program memory may also include a security application that uses the item weight data to track items in the checkout area. The display may be used to communicate with the consumer regarding movement of items in the checkout area.
The method of the present invention includes verifying placement of an item on a scale of a self-checkout station and adjusting the weighing of the item in response to a failure to sense a weight corresponding to the identification of the item placed on the scale. The adjustment may be an increase in the number of weight samples collected for verification so the likelihood of collecting a prerequisite number of samples within the toleration range for verification is increased. Alternatively, the adjustment may be an increase in the time between weight measurement samples. These adjustments increase the time required for measuring the weight of an item placed on a scale, however, they reduce the likelihood that the weight measured by the scale is erroneous because of temporary activities in the vicinity of the checkout station. Erroneous weight readings necessitate a consumer rescanning an item or a self-checkout attendant intervening in the checkout procedure. Thus, the method of the present invention reduces the occurrence of problems with self-checkout that are associated with erroneous weight measurements caused by temporary perturbations in the sensing of the weight on the scale of the self-checkout station.
It is an object of the present invention to provide a more robust scheme for measuring the weight of items placed on the scale of a self checkout station.
It is an object of the present invention to provide an adjustment to the process of determining the weight of an item placed on the scale of a self-checkout station so fluctuations are less likely to prevent the verification of a scanned item.
It is an object of the present invention to increase the time for determining the weight of a scanned item placed on the scale of a self-checkout station so that an accurate measurement of the item""s weight is not disturbed by temporary vibrations or additional weight.
These and other advantages and features of the present invention may be discerned from reviewing the accompanying drawings and the detailed description of the invention.